KR102576895B1 - Electro-optical displays - Google Patents

Abstract

An apparatus for driving an electro-optical display may include spaced apart first and second device layers and first and second rows of display pixels, each row may include a plurality of display pixels, each The display pixel has a pixel electrode located on a first device layer for driving the display pixel and a conductive line located on the second device layer and overlapping a portion of the pixel electrodes of the plurality of display pixels; And at least one conductive path connects the conductive line of the first row to the conductive line of the second row of display pixels.

Description

Electro-optical displays

Cross-reference to related applications

This application is related to and claims priority to U.S. Provisional Application No. 62/757,818, filed on November 9, 2018.

The entire disclosures of the foregoing applications are hereby incorporated by reference.

technology field

The present invention relates to electro-optical display devices and, more particularly, to display backplanes comprising thin film transistor arrays.

Particle-based electrophoretic displays have been the subject of intensive research and development for many years. In these displays, a plurality of charged particles (sometimes referred to as pigment particles) move through a fluid under the influence of an electric field. The electric field is typically provided by a conductive film or a transistor such as a field effect transistor. Electrophoretic displays have good brightness and contrast, wide viewing angle, state bistability and low power consumption compared to liquid crystal displays. Although these electrophoretic displays have slower switching speeds than LCD displays, electrophoretic displays are typically too slow to display real-time video. Additionally, electrophoretic displays can be slow at low temperatures because the viscosity of the fluid limits the movement of electrophoretic particles. Despite these drawbacks, electrophoretic displays can be found in everyday products such as electronic books (e-readers), cell phones and cell phone covers, smart cards, signs, watches, shelf labels, and flash drives.

Many commercial electrophoresis media essentially display only two colors, with a gradient between the black and white extremes, known as “grayscale.” These electrophoretic media use a single type of electrophoretic particle having a first color in a colored fluid having a second, different color (in which case the first color is displayed when the particles are placed adjacent to the viewing surface of the display). , the second color is displayed when the particles are spaced from the viewing surface) or using first and second types of electrophoretic particles with different first and second colors in an uncolored fluid. In the latter case, a first color is displayed when a particle of the first type is placed adjacent to the viewing surface of the display, and a second color is displayed when a particle of the second type is placed adjacent to the viewing surface of the display. Commonly the two colors are black and white.

Although seemingly simple, electrophoresis media and electrophoresis devices exhibit complex behavior. For example, simple "on/off" voltage pulses were found to be insufficient to obtain high-quality text in electronic readers. Rather complex "waveforms" are needed to drive the particles between states and ensure that the new displayed text does not retain memory, or "ghost", of the old text.

The present invention provides an electro-optical display having spaced apart first and second device layers and first and second rows of display pixels, each row comprising a plurality of display pixels, each display pixel having a pixel electrode located on the first device layer for driving and a conductive line located on the second device layer and overlapping a portion of the pixel electrodes of the plurality of display pixels; And at least one conductive path connects the conductive line of the first row to the conductive line of the second row of display pixels.

1 illustrates a backplane circuit according to the subject matter disclosed herein.
2 illustrates a top view of a display pixel according to the subject matter disclosed herein.
3A illustrates one embodiment of an equivalent circuit of a display pixel according to the subject matter disclosed herein.
3B illustrates a sample driving scheme according to the subject matter disclosed herein.
4A illustrates a backplane circuit according to the subject matter disclosed herein.
4B illustrates another backplane circuit according to the subject matter disclosed herein.
5A illustrates a display image with crosstalk according to the subject matter disclosed herein.
5B illustrates a display image with reduced crosstalk using the subject matter disclosed herein.

As indicated above, the subject matter presented herein provides methods and means for reducing capacitive coupling and improving electro-optic display performance.

The term "electro-optics", as applied to a material or display, is used herein in its conventional sense in imaging technology to refer to a material having first and second display states that differ in at least one optical property, the material having a The application of the electric field causes a change from the first display state of the material to the second display state of the material. The optical characteristic is typically color perceptible to the human eye, but it can also be pseudo-color in the sense of optical transmission, reflectance, luminescence, or, in the case of displays intended for machine readability, changes in reflectance for electromagnetic wavelengths outside the visible range. It may also be a different optical property.

The term “gray state” is used herein in its conventional sense in imaging technology to refer to a state intermediate between two extreme optical states of a pixel, and does not necessarily imply a black-white transition between these two extreme states. . For example, several E Ink patents and published applications referenced below describe electrophoretic displays where the extreme states are white and deep blue such that the intermediate “gray state” will actually be pale blue. In fact, as already mentioned, a change in optical state may not be a color change at all. The terms “black” and “white” may be used hereinafter to refer to the two extreme optical states of a display, and extreme optical states that are not strictly black and white, for example the white and dark blue states described above, are usually referred to as It should be understood as including. The term “monochrome” may be used hereinafter to denote a drive scheme that drives pixels into only their two extreme optical states with no intervening gray states.

The terms “bistable” and “bistable” are used herein in their ordinary sense in the art to refer to a display comprising display elements having first and second display states that differ in at least one optical property, Thus, after any given element has been driven by an addressing pulse of finite duration, the number of addressing pulses required to change the state of that display element so that that state assumes the first or second display state after the addressing pulse terminates. It will last for at least several times the minimum duration, for example at least four times. In Published US Patent Application No. 2002/0180687 (see also corresponding International Application Publication WO 02/079869), some particle-based electrophoretic displays capable of gray scale are described not only in their extreme black and white states, but also in their extreme black and white states. They are stable in their intermediate gray states, and this has been shown to be the case for some other types of electro-optic displays as well. This type of display is properly referred to as “multi-stable” rather than bistable, but for convenience, the term “bistable” may be used herein to cover both bistable and multi-stable displays.

The term “impulse” is used herein in its conventional sense of integration of voltage over time. However, some bistable electro-optic media act as charge transducers, and with such media an alternative definition of impulse, i.e. the integral of current over time (which is equal to the total charge applied), may be used. Depending on whether the medium operates as a voltage-time impulse transducer or as a charge impulse transducer, an appropriate definition of impulse should be used.

Several patents and applications assigned to or in the name of the Massachusetts Institute of Technology (MIT) and E Ink Corporation, describing encapsulated electrophoretic media, have recently been published. Such encapsulated media comprise several small capsules, each comprising an internal phase containing electrophoretically mobile particles suspended in a liquid suspension medium, and a capsule wall surrounding the internal phase. . Typically, the capsule itself is held within the polymer binder to form a coherent layer placed between the two electrodes. Technologies described in these patents and applications include:

(a) Electrophoretic particles, fluids and fluid additives; See, for example, U.S. Patent Nos. 7,002,728 and 7,679,814;

(b) capsules, binders, and encapsulation processes; See, for example, U.S. Patent Nos. 7,072,276 and 7,411,719;

(c) microcell structure, wall materials, and microcell formation method; See, for example, U.S. Patent Nos. 7,072,095 and 9,279,906;

(d) microcell filling and sealing method; See, for example, U.S. Patent Nos. 7,144,942 and 7,715,088;

(e) films and subassemblies containing electro-optic materials; See, for example, U.S. Patent Nos. 6,982,178 and 7,839,564;

(f) methods used for backplanes, adhesive layer and other auxiliary layers, and displays; See for example US Patents D485,294; 6,124,851; 6,130,773; 6,177,921; 6,232,950; 6,252,564; 6,312,304; 6,312,971; 6,376,828; 6,392,786; 6,413,790; 6,422,687; 6,445,374; 6,480,182; 6,498,114; 6,506,438; 6,518,949; 6,521,489; 6,535,197; 6,545,291; 6,639,578; 6,657,772; 6,664,944; 6,680,725; 6,683,333; 6,724,519; 6,750,473; 6,816,147; 6,819,471; 6,825,068; 6,831,769; 6,842,167; 6,842,279; 6,842,657; 6,865,010; 6,873,452; 6,909,532; 6,967,640; 6,980,196; 7,012,735; 7,030,412; 7,075,703; 7,106,296; 7,110,163; 7,116,318; 7,148,128; 7,167,155; 7,173,752; 7,176,880; 7,190,008; 7,206,119; 7,223,672; 7,230,751; 7,256,766; 7,259,744; 7,280,094; 7,301,693; 7,304,780; 7,327,511; 7,347,957; 7,349,148; 7,352,353; 7,365,394; 7,365,733; 7,382,363; 7,388,572; 7,401,758; 7,442,587; 7,492,497; 7,535,624; 7,551,346; 7,554,712; 7,583,427; 7,598,173; 7,605,799; 7,636,191; 7,649,674; 7,667,886; 7,672,040; 7,688,497; 7,733,335; 7,785,988; 7,830,592; 7,843,626; 7,859,637; 7,880,958; 7,893,435; 7,898,717; 7,905,977; 7,957,053; 7,986,450; 8,009,344; 8,027,081; 8,049,947; 8,072,675; 8,077,141; 8,089,453; 8,120,836; 8,159,636; 8,208,193; 8,237,892; 8,238,021; 8,362,488; 8,373,211; 8,389,381; 8,395,836; 8,437,069; 8,441,414; 8,456,589; 8,498,042; 8,514,168; 8,547,628; 8,576,162; 8,610,988; 8,714,780; 8,728,266; 8,743,077; 8,754,859; 8,797,258; 8,797,633; 8,797,636; 8,830,560; 8,891,155; 8,969,886; 9,147,364; 9,025,234; 9,025,238; 9,030,374; 9,140,952; 9,152,003; 9,152,004; 9,201,279; 9,223,164; 9,285,648; and Nos. 9,310,661; and U.S. Patent Application Publication No. 2002/0060321; 2004/0008179; 2004/0085619; 2004/0105036; 2004/0112525; 2005/0122306; 2005/0122563; 2006/0215106; 2006/0255322; 2007/0052757; 2007/0097489; 2007/0109219; 2008/0061300; 2008/0149271; 2009/0122389; 2009/0315044; 2010/0177396; 2011/0140744; 2011/0187683; 2011/0187689; 2011/0292319; 2013/0250397; 2013/0278900; 2014/0078024; 2014/0139501; 2014/0192000; 2014/0210701; 2014/0300837; 2014/0368753; 2014/0376164; 2015/0171112; 2015/0205178; 2015/0226986; 2015/0227018; 2015/0228666; 2015/0261057; 2015/0356927; 2015/0378235; 2016/077375; 2016/0103380; and 2016/0187759 issues; and International Application Publication No. WO 00/38000; See European Patent Nos. 1,099,207 B1 and 1,145,072 B1;

(g) color formation and color adjustment; See, for example, U.S. Patent Nos. 7,075,502 and 7,839,564;

(h) display driving method; See, for example, U.S. Patent Nos. 7,012,600 and 7,453,445;

(i) Application of displays; See, for example, U.S. Patent Nos. 7,312,784 and 8,009,348;

(j) U.S. Patent No. 6,241,921; and U.S. Patent Application Publication No. 2015/0277160; and non-electrophoretic displays, as described in U.S. Patent Application Publication Nos. 2015/0005720 and 2016/0012710.

All of the above patents and patent applications are incorporated by reference in their entirety.

Many of the aforementioned patents and applications state that the walls surrounding the individual microcapsules in an encapsulated electrophoretic medium are replaced by a continuous phase and thus the electrophoretic medium is comprised of a plurality of individual droplets of electrophoretic fluid and a continuous phase of polymeric material. It is possible to fabricate so-called polymer dispersed electrophoretic displays containing a phase, and the individual droplets of electrophoretic fluid within such polymer dispersed electrophoretic displays are capsules or micro It is recognized that what may be regarded as capsules: see, for example, 2002/0131147, supra. Therefore, for the purposes of the present application, these polymer-dispersed electrophoresis media are considered a subspecies of encapsulated electrophoresis media.

Encapsulated electrophoretic displays typically do not suffer from the clustering and settling failure modes of conventional electrophoretic devices and offer additional advantages, such as the ability to print or coat displays on a wide variety of flexible and rigid substrates. Provides benefits. (Use of the word "printing" includes, but is not limited to, pre-metered coatings, such as patch die coatings, slot or extrusion coatings, slide or cascade coatings, curtain coatings; roll coatings, such as knife over roll coatings, forward coatings, etc. and reverse roll coating; gravure coating; dip coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; silkscreen printing processes; electrostatic printing processes; thermal printing processes; inkjet printing processes. ; and other similar techniques.). Accordingly, the resulting display can be flexible. Additionally, because the display medium can be printed (using a variety of methods), the display itself can be manufactured inexpensively.

A related type of electrophoretic display is the so-called “microcell electrophoretic display”. In a microcell electrophoretic display, the charged particles and suspended fluid are not encapsulated within microcapsules, but instead are retained within a plurality of cavities formed within a carrier medium, typically a polymer film. For example, both Sipix Imaging, Inc. See International Application Publication No. WO 02/01281, assigned to, and published U.S. Application No. 2002/0075556.

Electro-optic displays of the aforementioned types are bistable and typically used in a reflective mode, but as described in certain of the aforementioned patents and applications, such displays have an electro-optic medium that adjusts the transmission of light. It can also be used to operate in "shutter mode", where the display operates in transmissive mode. Liquid crystals, including polymer dispersed liquid crystals, are of course also electro-optic media, but are typically not bistable and operate in a transmissive mode. Although certain embodiments of the invention described below are limited to use with reflective displays, other embodiments may be used with both reflective and transmissive displays, including conventional liquid crystal displays. In some embodiments, the electro-optic medium may be a rotationally dichroic member or an electrochromic medium.

Depending on whether the display is reflective or transmissive and whether the electro-optic medium used is bistable, to obtain a high-resolution display, individual pixels of the display must be addressable without interference from adjacent pixels. One way to achieve this goal is to provide an array of non-linear elements, such as transistors or diodes, with at least one non-linear element associated with each pixel, to produce an “active matrix” display. will be. The addressing or pixel electrode, which addresses one pixel, is connected to an appropriate voltage source through an associated non-linear element. Typically, when the non-linear element is a transistor, the pixel electrode is connected to the drain of the transistor, this arrangement will be assumed in the following description, but this is arbitrary in nature, and the pixel electrode may be connected to the source of the transistor. Typically, in high-resolution arrays, pixels are arranged in a two-dimensional array of rows and columns, such that any particular pixel is uniquely defined by the intersection of one specified row and one specified column. The sources of all transistors in each column are connected to a single column electrode, while the gates of all transistors in each row are connected to a single row electrode; Again, the assignment of sources to rows and gates to columns is conventional but essentially arbitrary and can be reversed if desired. The row electrodes are connected to a row driver, which applies a voltage to the selected row electrode to ensure that only one row is selected at any given moment, i.e., that all transistors in the selected row are conducting. This essentially ensures that a voltage is applied to all other rows while ensuring that all transistors in these non-selected rows remain non-conducting. The column electrodes are connected to column drivers, which impose selected voltages on the various column electrodes to drive the pixels in the selected row to their desired optical states. (The voltages mentioned above are conventionally provided from a non-linear array on opposite sides of the electro-optic medium and are relative to a common front electrode extending across the entire display.) After a pre-selected interval known as the "line address time", the selected row is The selection is deselected, the next row is selected, and the voltages on the column driver are changed to write the next line of the display. This process is repeated so that the entire display is written row by row.

Processes for manufacturing active matrix displays are well established. Thin film transistors can be manufactured using, for example, various deposition and photolithography techniques. A transistor includes a gate electrode, an insulating dielectric layer, a semiconductor layer, and source and drain electrodes. Application of voltage to the gate electrode provides an electric field across the dielectric layer, which dramatically increases the source-to-drain conductivity of the semiconductor layer. This change allows electrical conduction between the source and drain electrodes. Typically, the gate electrode, source electrode, and drain electrode are patterned. Typically, the semiconductor layer is also patterned to minimize stray conduction (i.e., crosstalk) between neighboring circuit elements.

Liquid crystal displays typically employ amorphous silicon (“a-Si”) thin film transistors (“TFTs”) as switching devices for the display pixels. Such TFTs typically have a bottom-gate configuration. Within one pixel, a thin film capacitor typically holds the charge transferred by the switching TFT. Electrophoretic displays may use similar TFTs with capacitors, but the function of the capacitors is somewhat different from that in liquid crystal displays; See previously co-pending application Ser. No. 09/565,413 and publications 2002/0106847 and 2002/0060321. Thin film transistors can be manufactured to provide high performance. However, manufacturing processes can incur significant costs.

In TFT addressing arrays, pixel electrodes are charged through the TFTs during line addressing time. During the line address time, the TFT is switched to the conducting state by changing the applied gate voltage. For example, for an n-type TFT, the gate voltage is switched to a “high” state to switch the TFT into a conducting state.

Additionally, undesirable effects, such as voltage shifts, may be caused by crosstalk occurring between the pixel electrode and the data line supplying the drive waveforms to the display pixel. Similar to the voltage shift described above, crosstalk between the data line and the pixel electrode causes capacitive coupling between the two even when the display pixel is not being addressed (e.g., the associated pixel TFT in depletion). It can be caused by . Such crosstalk can result in undesirable voltage shifts because it can induce optical artifacts such as image streaking.

In some embodiments, electrophoretic display or EPD 100 may include two substrates (e.g., plastic or glass), where a front plane laminate or FPL is positioned between the two substrates. In some embodiments, the lower portion of the top substrate may be coated with a transparent conductive material to function as a conductive electrode (i.e., V _com plane). The upper portion of the lower substrate may include an array of electrode elements (eg, conductive electrodes for each display pixel). A semiconductor switch, such as thin film transistors, or TFT, may be associated with each of these pixel electrodes. Application of a bias voltage to the pixel electrode and the V _com plane may result in electro-optic conversion of FPL. This optical conversion can be used as the basis for the display of text or graphical information on the EPD. In order to display a desired image, an appropriate voltage needs to be applied to each pixel electrode. To realize this, each TFT 102 may be provided with a gate line signal, a data line signal, a V _com line signal, and a storage capacitor. In one embodiment, as illustrated in FIG. 1 , the gate of each TFT 102 may be electrically coupled to a scan line 104 and the source or drain of the transistor may be connected to a data line 106. Alternatively, the two terminals of the storage capacitor may be connected to the V _com line 108 and the pixel electrode, respectively. In some embodiments, the V _com line grid on the lower portion of the upper substrate and the V _com line grid on the upper portion of the lower substrate may be connected to the same DC source.

EPD behavior and crosstalk

In operation, drive signals (eg, voltage pulses) are applied to the respective data lines to update the display pixels. To select which display pixels are to be updated, scan lines (e.g., scan line 104) allow drive signals from data lines (e.g., data line 106) to be applied to the corresponding display pixel. It may be selectively activated so that it may be applied to the pixel electrodes to update them. In some embodiments, each scan line may be activated sequentially until all of the display pixels of EPD 100 are updated. In this update process, the V _com signal may be disturbed or deviated from the intended level by unwanted capacitive coupling effects.

2 illustrates a top view of a display pixel 200 according to the subject matter disclosed herein. Display pixel 200 includes a pixel electrode 204 configured to drive the display pixel. In use, display pixel 200 will be driven by a series of voltage pulses induced on pixel electrode 204. A series of voltage pulses may be applied to the pixel electrode 204 via transistor 208. Transistor 208 may function as a switch that switches the signal path leading to pixel electrode 204 on and off. For example, gate 216 of transistor 208 may be connected to signal select gate line 202. In use, this gate 202 can be used to selectively turn on and off transistors 208 by applying or not applying a voltage to the gate 216 of transistors 208. Additionally, a series of voltage pulses may be supplied through data line 206. This data line 206 is also electrically coupled to transistor 208, as illustrated in FIG. 2. In operation, a signal (e.g., an electrical pulse) may be transmitted via gate line 202 to activate or turn on transistor 208 and, once transistor 208 is turned on, via data line 206. The applied electrical signals may be transmitted to the pixel electrode 204 through the transistor 208. Also shown in Figure 2 is the V _com line 210. In some embodiments, this V _com line 210 is electrically connected to the top electrode of the display (not shown here in Figure 2) to maintain the top electrode at an electrically constant voltage level (e.g., V _com ). It may also be coupled. Typically, this V _com line 210 is at the device level located below the pixel electrode 204. Also connected to this V _com line 210 is the electrode 214 of the storage capacitor, where the electrode 214 may be located on the same device layer as the V _com line 210.

At this time, referring to FIG. 3A, among the sources of capacitive coupling, one possible source may be the capacitance between the data line 304 and the V _com line 306 (i.e., C _DC 302). For example, when voltage signals are applied through data line 304, changes in the voltage levels on data line 304 may result in a capacitive coupling effect between data line 304 and V _com line 306. may occur. Another possible source of capacitive coupling may occur between the storage capacitor and the pixel electrode.

In operation, the V _com voltage value may experience fluctuations (e.g., a dip in the voltage value) when a display pixel is selected (i.e., when scan line 308 selects pixel 310), Drive voltage signals are applied through data line 304, causing changes in voltage values in data line 304. In this case, when affected by some of the capacitive effects mentioned above, the V _com voltage value may deviate from the target value (eg, +15, -15, or 0 V). When scan line 308 is turned off, V _com is not returnable to the target voltage value (i.e., leaving the selected display pixel floating). As a result, the voltage level of the selected pixel electrode shifts from the target value by approximately the below estimated amount, which may lead to an observable band along the V _com line direction. The shift in pixel voltage (ΔV _PIXEL ) can be calculated using the principle of charge conservation:

where ΔV _com is the resultant voltage shift in the value of V _com when the scan line is turned off, C _total is the total capacitance of the pixel electrodes, and C _total is the capacitance of the metal layers, in addition to the capacitive coupling effects mentioned above. and capacitive coupling effects that may occur between any of the material layers.

This shift in pixel voltage (ΔV _PIXEL ) may sometimes refer to crosstalk or stracking. One way to mitigate these undesirable effects may be to reduce the RC delay of the V _com signal to ensure that the V _com value returns to the target value or level during activation of the scan line. FIG. 3B illustrates that the V _com voltage 312 experiences a dip as the scan voltage 314, which turns on the pixel, is brought high (i.e., turns on pixel 310).

Regarding reducing the above-mentioned RC delay to ensure fast V level recovery, a new design of the display backplane is presented in Figure 4b. However, first, referring to Figure 4A, a conventional backplane 400 is presented. As illustrated in Figure 4A, each row of display pixels is biased by a V _com line 402, through which the V _com voltage is applied to each pixel. In FIG. 4A, the V _com signal lines for each line are shown as being independent from each other. In this configuration, when the V _com value is influenced or shifted by capacitive coupling effects caused by the storage capacitors and the data line (i.e. C _DC ) the V _com value is at the two ends of the pixel array. Recovery can only be achieved through applied voltages, which inherently may not be fast enough.

At this time, with reference to FIG. 4B, in the design 410 according to the subject matter presented herein, one V _com line 412 is connected to another V _com line 414 from an adjacent row using a conductive path 416. may be electrically coupled to, where the conductive path 416 may be constructed using materials commonly used in the prior art to construct electrically conductive lines (e.g., copper, gold, etc.). In this configuration, V _com current can then reach each of the pixel areas from the four sides of the pixel array, leading to reduced RC delay, which results in faster V _com recovery time.

In practice, an EPD may have two adjacent rows of display pixels, where each row is multiple?? It may include a plurality of display pixels, and each display pixel has a pixel electrode for driving the display pixel. And each row also has a first signal line connected to each of the pixel electrodes of the plurality of display pixels, and at least one connecting a first signal line of the first row to a second signal line of a second row of display pixels. It may also have a conductive path. Or as illustrated in FIG. 4B, more than one, for example 2 or 3 or 4 such conduction paths exist between adjacent rows of display pixels.

In another embodiment, as described in FIG. 2 above, an EPD may have spaced apart first and second device layers and first and second rows of display pixels, where each row has a plurality of display pixels. and each display pixel has a pixel electrode on the first device layer for driving the display pixel. Additionally, the signal line is located on the second device layer and overlaps a portion of the pixel electrodes of the plurality of display pixels, and at least one conductive path connects the signal line of the first row to the signal line of the second row of display pixels. I order it.

Figure 5A illustrates an image displayed using the backplane illustrated in Figure 4A, where crosstalk effects are present. In comparison, Figure 5b illustrates an image using the backplane illustrated in Figure 4b, where crosstalk effects are reduced.

From the foregoing, it will be seen that the present invention can provide a backplane for reducing display pixel voltage shifts. It will be apparent to those skilled in the art that numerous changes and modifications may be made in the specific embodiments of the invention described above without departing from the scope of the invention. Accordingly, all of the foregoing description should be interpreted in an illustrative sense rather than a restrictive sense.

Claims (11)

delete delete delete An electro-optical display having spaced first and second device layers and a plurality of rows of display pixels, comprising:
Each row of the plurality of rows of display pixels:
Having a plurality of display pixels, each display pixel having:
a pixel electrode positioned on a first device layer configured to drive the display pixel with a series of voltage pulses supplied through a data line;
a V _COM signal line located on the second device layer and overlapping a portion of the pixel electrode;
a gate line parallel to the V _COM signal line; and
connecting the V _{COM signal line of the first row of the plurality of display pixels only to the V COM signal} line of the second row of the plurality of rows of display pixels adjacent to the first row of the plurality of rows of display pixels. Electro-optical display with conductive paths. According to claim 4,
and the conductive path is located on the second device layer. According to claim 4,
An electro-optical display further comprising an electro-optic medium. According to claim 6,
An electro-optical display, wherein the electro-optic medium is a rotating dichroic member or an electrochromic medium. According to claim 6,
An electro-optic display, wherein the electro-optic medium is an electrophoretic medium comprising a plurality of charged particles capable of moving in and through the fluid upon application of an electric field to the electro-optic medium. According to claim 4,
A second conductive path spaced apart from the conductive path in a direction parallel to the V _COM signal line, the second conductive path connecting the V _COM signal line of the first row of the plurality of rows of display pixels to a DC source only. An electro-optical display further comprising a second conductive path that electrically couples. According to claim 4,
Each of the plurality of display pixels further includes a first capacitance formed between the pixel electrode and the V _COM signal line. According to claim 10,
Each of the plurality of display pixels further includes a second capacitance formed between the data line and the V _COM signal line.

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